Walmart's free service, called NextDay, requires an order of at least $35. The one-day service is now operating in select cities but will be most places soon.

Walmart rolls out NextDay

With next-day service already in Phoenix and Las Vegas, Walmart says Southern California will be going online "within days."

"It will roll out gradually over the coming months, with a plan to reach approximately 75% of the U.S. population this year, which includes 40 of the top 50 major U.S. metro areas," wrote Marc Lore, Walmart eCommerce U.S. president and CE, in his blog.

While announcing its NextDay program, the company also said that by the end of the year it plans to offer Grocery Pickup from 3,100 stores and same-day Grocery Delivery from 1,600 stores. Walmart operates 4,700 stores across the nation.

How Walmart's NextDay works

According to Walmart, the NextDay delivery offers up to 220,000 of the items most frequently purchased, ranging from diapers and laundry detergent to toys and electronics. The specific assortment of NextDay items will vary by customer location.

Here's how to use Next Day:

Visit Walmart.com and toggle into NextDay delivery to view items that are eligible for the service.

After adding items into your cart, you can proceed to checkout.

Everything in the cart must be eligible for NextDay delivery to qualify for the free service. Order cut-off times vary by location.

Amazon trashing millions of unsold items

Amazon was revealed to have potentially destroyed millions of unsold items in various countries. This is a shocking move, as these products are good as new -- making donation the more logical choice of disposal.